Ac ompetitive complexation strategy has been developed to construct an ovel electrocatalyst with Zn-Co atomic pairs coordinated on Nd oped carbon support (Zn/ CoN-C). Sucha rchitecture offers enhanced binding ability of O 2 ,s ignificantly elongates the O À Ol ength (from 1.23 to 1.42 ), and thus facilitates the cleavage of O À Ob ond, showing at heoretical overpotential of 0.335 Vd uring ORR process.A saresult, the Zn/CoN-C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions with ah alf-wave potential of 0.861 and 0.796 Vr espectively. The in situ XANES analysis suggests Co as the active center during the ORR. The assembled zinc-air battery with Zn/CoN-Ca sc athode catalyst presents am aximum power density of 230 mW cm À2 along with excellent operation durability.T he excellent catalytic activity in acid is also verified by H 2 /O 2 fuel cell tests (peak power density of 705 mW cm À2 ).

capacity of the modified oxide reaches 320 mAh g -1 in the initial cycle, 94.5% of which remains after 100 cycles. More importantly, the average discharge potential drops only by 136 mV in this process. Our findings illustrate the importance of inactivating the surface oxygen in suppressing the cation mixing in the bulk, providing an effective strategy for designing high-performance Li-rich cathode materials.

Carbonate-based electrolytes demonstrate safe and stable electrochemical performance in lithium-sulfur batteries. However, only a few types of sulfur cathodes with low loadings can be employed and the underlying electrochemical mechanism of lithium-sulfur batteries with carbonate-based electrolytes is not well understood. Here, we employ in operando X-ray absorption near edge spectroscopy to shed light on a solid-phase lithium-sulfur reaction mechanism in carbonate electrolyte systems in which sulfur directly transfers to Li2S without the formation of linear polysulfides. Based on this, we demonstrate the cyclability of conventional cyclo-S8 based sulfur cathodes in carbonate-based electrolyte across a wide temperature range, from −20 °C to 55 °C. Remarkably, the developed sulfur cathode architecture has high sulfur content (>65 wt%) with an areal loading of 4.0 mg cm−2. This research demonstrates promising performance of lithium-sulfur pouch cells in a carbonate-based electrolyte, indicating potential application in the future.

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The application of Li-S batteries is hindered by low sulfur utilization and rapid capacity decay originating from slow electrochemical kinetics of polysulfide transformation to Li 2 S at the second discharge plateau around 2.1 V and harsh shuttling effects for high-S-loading cathodes. Herein, a cobalt-doped SnS 2 anchored on N-doped carbon nanotube (NCNT@Co-SnS 2 ) substrate is rationally designed as both a polysulfide shield to mitigate the shuttling effects and an electrocatalyst to improve the interconversion kinetics from polysulfides to Li 2 S. As a result, high-S-loading cathodes are demonstrated to achieve good cycling stability with high sulfur utilization. It is shown that Co-doping plays an important role in realizing high initial capacity and good capacity retention for Li-S batteries. The S/NCNT@Co-SnS 2 cell (3 mg cm −2 sulfur loading) delivers a high initial specific capacity of 1337.1 mA h g −1 (excluding the Co-SnS 2 capacity contribution) and 1004.3 mA h g −1 after 100 cycles at a current density of 1.3 mA cm −2 , while the counterpart cell (S/NCNT@SnS 2 ) only shows an initial capacity of 1074.7 and 843 mA h g −1 at the 100th cycle. The synergy effect of polysulfide confinement and catalyzed polysulfide conversion provides an effective strategy in improving the electrochemical performance for high-sulfur-loading Li-S batteries.

A competitive complexation strategy has been developed to construct a novel electrocatalyst with Zn‐Co atomic pairs coordinated on N doped carbon support (Zn/CoN‐C). Such architecture offers enhanced binding ability of O2, significantly elongates the O−O length (from 1.23 Å to 1.42 Å), and thus facilitates the cleavage of O−O bond, showing a theoretical overpotential of 0.335 V during ORR process. As a result, the Zn/CoN‐C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions with a half‐wave potential of 0.861 and 0.796 V respectively. The in situ XANES analysis suggests Co as the active center during the ORR. The assembled zinc–air battery with Zn/CoN‐C as cathode catalyst presents a maximum power density of 230 mW cm−2 along with excellent operation durability. The excellent catalytic activity in acid is also verified by H2/O2 fuel cell tests (peak power density of 705 mW cm−2).

Solid‐state electrolytes (SEs) with high anodic (oxidation) stability are essential for achieving all‐solid‐state Li‐ion batteries (ASSLIBs) operating at high voltages. Until now, halide‐based SEs have been one of the most promising candidates due to their compatibility with cathodes and high ionic conductivity. However, the developed chloride and bromide SEs still show limited electrochemical stability that is inadequate for ultrahigh voltage operations. Herein, this challenge is addressed by designing a dual‐halogen Li‐ion conductor: Li3InCl4.8F1.2. F is demonstrated to selectively occupy a specific lattice site in a solid superionic conductor (Li3InCl6) to form a new dual‐halogen solid electrolyte (DHSE). With the incorporation of F, the Li3InCl4.8F1.2 DHSE becomes dense and maintains a room‐temperature ionic conductivity over 10−4 S cm−1. Moreover, the Li3InCl4.8F1.2 DHSE exhibits a practical anodic limit over 6 V (vs Li/Li+), which can enable high‐voltage ASSLIBs with decent cycling. Spectroscopic, computational, and electrochemical characterizations are combined to identify a rich F‐containing passivating cathode‐electrolyte interface (CEI) generated in situ, thus expanding the electrochemical window of Li3InCl4.8F1.2 DHSE and preventing the detrimental interfacial reactions at the cathode. This work provides a new design strategy for the fast Li‐ion conductors with high oxidation stability and shows great potential to high‐voltage ASSLIBs.

Atomic Fe-doped hollow carbon nanopolyhedra as efficient ORR catalysts.